1. Glock Automatic Pistol
2. A pistol in general
orginally it was a acronym for Glock Automatic Pistol but some people can't tell the differents between a glock and a desert eagle so you may her some people use the term gap when refering to a Beretta

GAPs are used in times if you spot or hear something geeky/nerdy and you like it, you give someone Geeky Awesomeness Points to that person by saying "GAPs" just like the word 'gaps' and not spelling out the abbreviation. There's no real point system in giving out or receiving GAPS, just how many times you hear people calling you it shows how Geeky and Awesome you are. :)

Geek 1: "Dude, check out my ringtone!" *Are You Still There?*
Geek 2: "Portal FTW! You, good sir, have just earned some GAPs!"